Self-powered fitness equipment

ABSTRACT

A self-powered fitness device to simulate various types of stepping motions is provided. The device includes a frame ( 10 ), a guide ( 20 ) movably associated with the frame, and first and second foot supports ( 22   a,    22   b ) coupled to the guide. The device further includes a generator ( 32 ) coupled to the first and second foot supports, which is actuated to produce power by the user&#39;s stepping motions. The device also includes a battery coupled to the generator to store at least part of the power produced by the generator. Finally, the device includes a lift system ( 24 ) for automatically changing at least one of the elevation and the angular orientation of the guide relative to the frame. Since the lift system is powered by both the generator and the battery, actuation of the lift system will not alter the resistance to the user pedaling the foot supports during exercising.

FIELD OF THE INVENTION

[0001] The present invention relates to exercise equipment, and morespecifically to a self-powered stationary exercise device including astorage battery for actuating certain components of the exercise deviceso as to maintain the resistance felt by the user substantially constantduring the device's use.

BACKGROUND OF THE INVENTION

[0002] A stationary exercise device that can simulate a wide range ofstepping motions, including skiing, walking, jogging, running andclimbing, is known under the trademark of EFX Elliptical FitnessCrosstraining® and is available from Precor Incorporated of Bothell,Wash. Some embodiments of Elliptical Fitness Crosstraining® machines aredescribed in U.S. Pat. No. 6,146,313, which is explicitly incorporatedby reference herein.

[0003] Briefly, referring to FIG. 1, an Elliptical FitnessCrosstraining® machine includes a floor engaging frame 10 incorporatinga forward post 12. A pair of flywheels 14 a and 14 b (overlapping witheach other and thus only flywheel 14 a is shown) are located at the rearof the frame 10 for rotation about a horizontal, transverse axis 16. Therearward ends of foot links 18 a and 18 b are pivotally attached tocorresponding flywheels 14 a and 14 b to travel about a circular patharound axis 16 as the flywheels rotate. The forward ends of foot links18 a and 18 b are movably mounted to an adjustable guide 20. The forwardends of foot links 18 a and 18 b are adapted to ride along guide 20, toreciprocate back and forth therealong, as the rearward ends of footlinks 18 a and 18 b rotate about axis 16, causing foot pedals (or footsupports) 22 a and 22 b carried by the foot links to travel alongvarious elliptical paths. Specifically, FIG. 1 shows the path of travelof the foot pedal at three different angular orientations of guide 20corresponding to different elevations of a lift system 24. In thesmallest angular orientation (approximately 10° above the horizontal),the corresponding foot pedal travel path 26 is illustrated. Thisgenerally corresponds to a gliding or cross-country skiing motion. Theguide 20 is shown at a second orientation at a steeper angle,approximately 20° from the horizontal, with the corresponding foot pedaltravel path 28. This path of travel generally corresponds to a walkingmotion. FIG. 1 also illustrates a third, even steeper, angularorientation of the guide 20, approximately 30° from the horizontal, withthe corresponding foot pedal travel path 30. This path of travelgenerally corresponds to a climbing motion. Additionally oralternatively to changing the angular orientation of guide 20, changingthe elevation of guide 20 relative to the frame 10 will also cause thepath of travel of the foot pedals to change. The Elliptical FitnessCrosstraining® machine of this type is connectable to a standardamperage AC power supply.

SUMMARY OF THE INVENTION

[0004] The present invention is directed to providing self-poweredfitness equipment, such as a self-powered Elliptical FitnessCrosstraining® machine.

[0005] Specifically, a self-powered fitness device to simulate varioustypes of stepping motions is provided. The device includes a frame, aguide movably associated with the frame, and at least one foot supportcoupled to the guide. The foot support is configured to receive a user'sfeet. The device further includes a generator drivably coupled to thefoot support. The generator is activated to produce power by the user'sstepping motions on the foot support. The device also includes a batterycoupled to the generator to store at least part of the power produced bythe generator. Finally, the device includes a lift system forautomatically changing at least one of the elevation and the angularorientation of the guide relative to the frame. Since the lift system ispowered by both the generator and the battery, actuation of the liftsystem will not alter the resistance to the user pedaling the footsupport during exercising.

[0006] In accordance with one aspect of the present invention, thedevice may be configured so that the battery will power the device for apredefined period of time even after the user stops pedaling.

[0007] As will be apparent to those skilled in the art, the use of abattery to activate an actuator (e.g., a lift system) of a fitnessdevice so as to maintain a substantially constant resistance to the usercan be applied in various types of fitness equipment, and is not limitedto an Elliptical Fitness Crosstraining® machine.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The foregoing aspects and many of the attendant advantages ofthis invention will become more readily appreciated as the same becomebetter understood by reference to the following detailed description,when taken in conjunction with the accompanying drawings, wherein:

[0009]FIG. 1 is a side elevational view of an Elliptical FitnessCrosstraining® machine shown in schematic form, illustrating the pathsof the user's foot at different angular orientations of a guide for footpedals, as known in the prior art;

[0010]FIG. 2 is a perspective view of a self-powered Elliptical FitnessCrosstraining® machine formed in accordance with the present invention;and

[0011]FIG. 3 is a block diagram illustrating electrical components ofthe self-powered Elliptical Fitness Crosstraining® machine formed inaccordance with the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0012] Referring to FIG. 2, a self-powered fitness device to simulatevarious types of stepping motions in accordance with the presentinvention includes a frame 10, a guide 20 movably associated with theframe, and a pair of foot pedals (foot supports) 22 a and 22 b carriedby elongated foot links 18 a and 18 b. The forward ends of the footlinks 18 a and 18 b are movably supported by the guide 20. The devicefurther includes a lift system 24 (enclosed in a forward hood 25) forselectively and automatically changing at least one of the elevation andangular orientation of the guide 20 relative to the frame 10. Thus, theuser may readily adjust the guide 20 to simulate a wide range ofstepping motions. These components are generally equivalent to thosedisclosed in U.S. Pat. No. 6,146,313 referred to in the backgroundsection above.

[0013] Referring additionally to FIG. 3, in accordance with the presentinvention, the self-powered fitness device still further includes agenerator 32 (enclosed in a rearward hood 34) drivably coupled to thefirst and second foot links 18 a and 18 b. The generator 32 is actuatedto produce power by the user's stepping motions when the user's feet arein the first and second foot pedals 22 a and 22 b. In one embodiment,the generator 32 is formed of a three-phase AC generator including a DCpermanent-magnet alternator, which produces a sinusoidal voltageproportional to its rotational speed (RPM). To actuate the generator 32by the user's stepping motions, the generator is drivably coupled withthe flywheels 14 a and 14 b coupled to the foot links 18 a and 18 b (seeFIG. 1) using any suitable transmission means such as a shaft, chain,transmission, or belt (not shown). The generator 32 is designed so as toproduce a voltage even when a user is pedaling at very low speeds. Theresistance on the pedals for the user is controlled by a resistancecontroller 36 based on the amount of current being demanded from thegenerator 32, i.e., the more current is demanded from the generator 32,the higher the level of torque required to power the generator 32, andthe higher the resistance on the pedals. For example, this can beaccomplished by a CPU/microprocessor 60 determining the amount ofcurrent being demanded from the generator 60, and sending acorresponding command signal to the resistance controller 36. Theresistance controller 36 responds by sending a corresponding fieldcurrent signal (e.g., pulse width modulated signal) to the generator 32.Changes in the field current signal varies the field current in thealternator in the generator 32, i.e., increasing current in thealternator field tends to increase the strength of its magnetic field,thereby increasing resistance of the alternator to the user; anddecreasing current in the alternator field tends to decrease thestrength of its magnetic field, thereby decreasing resistance of thealternator to the user. The field current signal may be varied by theuser's programming for imparting a desired level of resistance to theuser. The voltage produced by the generator 32 is used to power variouscomponents of the self-powered fitness device, as will be more fullydescribed below.

[0014] This arrangement, without more, would require that wheneversubstantially more current is demanded from the generator 32, for thepurpose of actuating the guide 20 in this example, the resistance on thepedals for the user will be increased. This is undesirable when the userwishes to continue exercising while maintaining a substantially constantresistance to his/her stepping motions.

[0015] Accordingly, still referring to FIG. 3, the present inventionprovides a novel arrangement of a battery 48 to actuate the lift system24 to move the guide 20 up and down, so as to maintain the resistance tothe user substantially constant during exercising regardless of whetherthe guide 20 is activated or not. Specifically, according to the presentinvention, the voltage from the generator 32 is rectified and convertedinto DC voltage via an AC-DC converter 38, which will then power auniversal power supply 40. The universal power supply 40 will create anisolated power supply 42 (for example, 18 volts) and a non-isolatedpower supply 44 (for example, 12 volts). For safety regulationspurposes, the 18-volt isolated power supply 42 is connected to a digitalground, which is isolated from the non-isolated power supply 44connected to an analog ground, to completely isolate those componentsthat may contact the user from any circuits powered directly from the ACgenerator 32 (see “isolation barrier” line in FIG. 3). The non-isolatedpower supply 44 is used to operate the resistance controller 36.

[0016] In one embodiment, the 18-volt isolated power supply 42 is thenconverted into 14.5 volts for a battery charger 46 for charging thebattery 48, which will be used to power the DC guide lift motor(actuator) 24 to move the guide 20 up and down, under the control of alift controller 52. In place of a conventional battery, any type ofelectric energy storage medium may be used, as will be apparent to thoseskilled in the art. The isolated power supply 42 is also converted into8 volts via a DC-DC converter 54 to power a display panel 56 of thefitness device. (See FIG. 2, also.) As well known in the art, thedisplay 56 includes one or more display screens and a command consolecomposed of a number of depressible buttons. The display screens areused for presenting various information useful to the user, while thecommand console is used to allow the user to activate or program thedevice. The 8 volts from the DC-DC converter 54 is further converted to5 volts via a linear regulator 56 for powering a CPU and otherperipherals 60. The CPU 60 coordinates the operation of the liftcontroller 52, the upper display 56, and the resistance controller 36.

[0017] Importantly, because the battery 48 is used to power the guide20, actuating the guide 20 will not produce a change in the resistanceon the pedals 22 a and 22 b felt by the user (except when the user'sprogramming changes the current being demand from the generator 32). Thenormal guide duty cycle operation is typically 16.6%, meaning that foreach minute that the guide 20 is actuated (“on”), there will be 5minutes that the guide 20 is not actuated (“off”). Accordingly, thebattery 48 is configured to be charged during the “off” cycle, and then,during the “on” cycle, the 14.5 volts from the battery charger 46supplies some of the current for actuating the guide 20 while thebattery 48 will provide the rest. Consequently, while the user ispedaling, the whole system is powered using solely the energy providedby the user, and the resistance on the pedals will not change even whenthe guide 20 is actuated. Furthermore, the battery 48 may be used topower the guide 20, and also maintain the CPU 60 and the display panel56, for up to 20-30 seconds after the user stops pedaling.

[0018] While the preferred embodiments of the invention have beenillustrated and described, it will be appreciated that various changescan be made therein without departing from the spirit and scope of theinvention. For example, while the self-powered fitness device of thepresent invention was described in specific reference to a EllipticalFitness Crosstraining® machine of the type described in U.S. Pat. No.6,146,313, the invention may be incorporated in other types ofself-powered fitness devices with an actuatable component (e.g., aguide) in order to maintain the resistance for the user substantiallyconstant regardless of actuation of the component. Thus, any devicewherein a user may translate exercise of any portion of the body intoelectric power via a generator (e.g., rowing machines, treadmills, stairclimbers, weight machines, exercise cycles, etc.) can incorporate thepresent invention.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:
 1. A self-powered fitnessdevice to simulate various types of stepping motions, comprising: aframe; a guide movably associated with the frame; a foot support forreceiving a user's feet, the foot support being coupled to the guide; agenerator coupled to the foot support, the generator being actuated toproduce electric power by the user's stepping motions acting on the footsupport; an electric energy storage medium coupled to the generator tostore at least part of the power produced by the generator; a liftsystem for selectively and automatically changing at least one of theelevation and the angular orientation of the guide relative to theframe, the lift system being powered by both the generator and theelectric energy storage medium; and a microprocessor coupled to thegenerator, the electric energy storage medium, and the lift system forcoordinating their respective operations, the microprocessor beingpowered by the generator.
 2. The device of claim 1, wherein thegenerator comprises a three-phase AC generator.
 3. The device of claim1, wherein the electric energy storage medium comprises a battery. 4.The device of claim 1, further including a resistance controller forselectively adjusting the resistance applied to the foot support, theresistance controller being coupled to the microprocessor to maintainthe resistance substantially constant regardless of whether the liftsystem is actuated or not.
 5. The device of claim 4, wherein theresistance controller selectively adjusts the resistance applied to thefoot support as a function of a field current.
 6. The device of claim 1,wherein the electric energy storage medium is used to power the devicefor a predetermined period of time after the user stops pedaling.
 7. Thedevice of claim 1, wherein the foot support comprises first and secondfoot supports for receiving the user's left and right feet,respectively.
 8. The device of claim 1, further comprising a displaypanel attached to the frame, the display panel being coupled to themicroprocessor, wherein at least part of the power produced by thegenerator is not stored in the electric energy storage medium and isused to power the display panel.
 9. A self-powered fitness device,comprising: a frame; an actuatable component associated with the frame;an exercise input unit that translates exercise of a portion of a user'sbody into a predefined motive force; a generator coupled to the exerciseinput unit, the generator being activated to produce electric power bythe user's exercising motions via the exercise input unit; an electricenergy storage medium coupled to the generator to store at least part ofthe power generated by the generator; and an actuator for selectivelyand automatically actuating the actuatable component, the actuator beingpowered by both the generator and the electric energy storage medium.10. The device of claim 9, wherein the actuatable component comprises aliftable guide.
 11. The device of claim 9, wherein the generatorcomprises a three-phase AC generator.
 12. The device of claim 9, whereinthe electric energy storage medium comprises a battery.
 13. The deviceof claim 9, further including a resistance controller for selectivelyadjusting the resistance applied to the exercise input unit to be feltby the user, the resistance controller being configured to maintain theresistance substantially constant regardless of whether the actuator isactuated or not.
 14. The device of claim 13, wherein the resistancecontroller selectively adjusts the resistance applied to the exerciseinput unit as a function of a field current.
 15. The device of claim 9,wherein the electric energy storage medium is used to power the devicefor a predetermined period of time after the user stops exercising. 16.A method of self-powering a fitness device, comprising: providing afitness device comprising a frame, an actuatable component associatedwith the frame, an exercise input unit that translates exercise of aportion of a user's body into a predefined motive force, a generatorcoupled to the exercise input unit, an electric energy storage mediumcoupled to the generator, and an actuator for selectively andautomatically actuating the actuatable component; allowing the user toexercise using the exercise input unit on the fitness device; producingpower via the generator based on the user's exercising motions; storingat least part of the power generated by the generator in the electricenergy storage medium; and powering the actuator for the actuatablecomponent with both the generator and the electric energy storagemedium.
 17. The method of claim 16, wherein the fitness device comprisesa self-powered fitness device to simulate various types of steppingmotions, the actuatable component comprising a guide, the exercise inputunit comprising at least one foot support, and the actuator comprising alift system for selectively lifting the guide.
 18. The method of claim16, wherein the electric energy storage medium comprises a battery. 19.The method of claim 16, wherein the step of powering the actuatorfurther comprises maintaining the resistance applied to the exerciseinput unit substantially the same as the resistance applied to theexercise input unit when the actuator is not being powered.
 20. Themethod of claim 16, further comprising the step of powering the devicewith the electric energy storage medium for a predetermined period oftime after the user stops exercising.